1. Field of the Invention
The present invention generally relates to a copying apparatus having a copying section for copying an image onto a copying photosensitive material in accordance with copying conditions wherein the copying conditions are corrected on the density of the density of the copied image. More particularly, the present invention concerns a copying apparatus having a light.attenuating filter for facilitating the setting of copying conditions, such as standard exposure conditions set when the copying apparatus is initially used, and the determination of the standard exposure conditions that are reset when changes occur with respect to the copying apparatus and a developing solution, as well as a print evaluating method for evaluating the quality of prints obtained from the film using this copying apparatus, a method for setting printing conditions for setting standard exposure conditions for obtaining high print quality, and a controller for controlling the copying apparatus.
2. Description of the Related Art
In photofinishing laboratories at large, a negative film is subjected to development in a film processor, and an image on the negative film developed is printed onto a printing paper by means of a color printer. Then, the printed paper is developed by a paper processor, thereby obtaining a print from the photographed film. In recent years, a printer-processors in which a printer and a paper processor are combined have become widespread, and the operation is effected in a manner similar to the one described above. When a developing solution is used for extended periods of time, it becomes impossible to maintain its proper performance owing to the influence of such as a lack of a replenishing solution, oxidation with air, evaporation of the solution, the mixing in of the solution of a preceding process, and so on. For this reason, in order to constantly maintain the quality of prints in good conditions, it is necessary to constantly control the developing solution in the film processor and and the developing solution in the paper processor or the printer-processor. Accordingly, the following measure has conventionally been adopted: First, a film development. evaluating control strip prepared by exposing a film in advance under a plurality of conditions is passed through the film processor, and a paper development-evaluating control strip prepared by exposing in advance the paper under a plurality of conditions is also passed through the paper processor or the processor section of the printer-processor. Then, a density measurement is made of the developed film or the print so as to confirm the presence or absence of any abnormality in the film developing solution or the paper developing solution.
Storage of the film development-evaluating control strip in a refrigerator is facilitated since it is supplied by being contained in a film container. In addition, by connecting this control strip to a film reader, it merely suffices to set the control strip in a film.inserting portion of the film processor. The paper development-evaluating control strip, on the other hand, is so large that it is difficult to be stored in the refrigerator. In addition, it is necessary to accommodate the paper development-evaluating control strip in a case when the control strip is set in the paper processor or the printer-processor, and it is also necessary to push out the control strip with the case being set. Hence, there has been the problem that skill and labor are required in inserting the control strip into the developing section.
As described above, since the film development-evaluating control strip can be readily set, the control strip can be handled relatively easily, and a film developing solution generating has a more stable performance than a paper developing solution. As for the paper developing solution, on the other hand, although its performance is susceptible to change, the present situation is such that it is not controlled sufficiently since the handling of the paper development-evaluating control strip is troublesome, as described above.
In addition, in order to constantly finish color prints with high quality by means of the printer and the processor or the printer.processor, it is essential to properly effect development processing by controlling the developing solutions and properly set the standard exposure conditions of the printer or the printer section of the printer-processor, as described above. For this reason, the standard exposure conditions are set at the time of setting the printer or the printer.processor, Nevertheless, it is necessary to correct and reset the standard exposure conditions since the printing conditions change in cases such as where a color paper having a different emulsion number, where an exposing lamp (printer lamp) of the exposing section is replaced, where the developing solution is replaced, and where the contents of the photograph have undergone a change from a colorful one to a less colorful one or vice versa due to a change of the season or the like. Also, printing conditions change owing to the staining or deterioration of a light source system including a light-adjusting filter, a halogen lamp, and a reflector or replacement thereof, so that it is necessary to correct and reset the standard exposure conditions in the same way as described above. In correcting the standard exposure conditions, by using a reference negative film having a portion corresponding to an average subject color around a portion corresponding to a negative on which a gray subject has been photographed, the correction is made by comparing a density of a test print printed and developed from this reference negative film and a density (targeted density) of a reference print subjected in advance to printing and development. That is, since the reference negative film has a standard subject density and a medium.gray subject density, the standard exposure conditions are corrected in such a manner that the print obtained from the reference negative film will be developed into the medium gray color.
In addition to the film and paper development-evaluating control strips, the aforementioned reference negative film is used for setting the standard exposure conditions to control the printer conditions and the light source, as described above. This reference negative film is supplied after being developed in a standard developing solution by a film manufacturer or the like, and has not been developed by the film processor which is used actually. Consequently, the standard exposure conditions set by using the reference negative film are not necessarily appropriate in photofinishing laboratories. Furthermore, since the density values obtained from the aforementioned control strips are used to evaluate only the respective processes, it is difficult to estimate the final print quality, which has been a factor leading to distrust and a lack of interest in control.
In addition, with the above.described method, there are drawbacks in that since the reference negative film is used, the correction accuracy can decline with the discoloration of the reference negative film, and that since the reference negative film is set on the negative carrier, the correction accuracy can decline due to the staining of the reference negative film. Also, since it is necessary to prepare the reference negative film for each type of film, there is another drawback in that the burden imposed on the operator increases as the number of film types increases.
To overcome these drawbacks, Japanese Patent Laid-Open Publication No. 60-113233 discloses an arrangement wherein a flap is provided on which a test film for preparing a test copy is disposed in abutment with the copying material, and the test copy is prepared on the copying material so as to obtain proper exposure conditions. This method has an advantage in that the lowering of correction accuracy due to staining can be prevented since the test film is automatically set. However, since the test film is used, the problem of discoloration occurs in the same way as described above. Additionally, since the test film abuts against the copying material, it is impossible to photometrically measure the light source system, so that there has been a drawback in that it is impossible to distinguish whether the change in the exposure conditions is due to the light source system of the printer or the printer-processor or due to the copying material and development processing (due mainly to the deterioration of the developing solution), making it impossible to correct the exposure conditions for each cause of the occurrence of the change. In addition, if the light source system is photometrically measured directly, electric charges become saturated at a measuring position, making it impossible to effect photometry at the position of the light-adjusting filter and through the light-adjusting filter. Hence, it is necessary to attenuate the light by inserting the reference negative film or the like between a photometer and the light source. However, disposing the negative film or the like between the photometer and the light source results in an undesirable drawback of discoloration and a change in the density due to heat.
The movement of a perforated plate into the path of the exposing light to prevent saturation of the photometer is conducted in a cut-filter method in which red (R), green (G), and blue (B) components of light are respectively cut by inserting a filter comprising cyan (C), magenta (M), and yellow (Y) filters, and in an additive color printing method in which the R, G, and B components of light are formed by the R, G, and B filters to independently control exposure amount, respectively. However, in a case where the perforated plate is used in a light-adjusting filter method in which the C, M, and Y filters are inserted into the optical path to control the exposure amount of R, G, and B through the amount of insertion, there is a drawback in that if the size of the perforations are large, the amount of light transmitted through the perforated plate varies abruptly owing to the movement of the light-adjusting filter, so that the photometric value does not vary smoothly. If the size of the perforations is made small, the amount of light varies by becoming loaded with dust and the like.
With the above.described printer-processor, to control and maintain standard exposure conditions, control of the state of the printer-processor is conducted by describing the test print density and the state of the developing solutions on a control chart. By using such a control chart, it is possible to determine the tendency of changes regarding the printer-processor, and so on.
With the conventional techniques, however, there have been drawbacks in that no function is provided for automatically obtaining control data, that it is time-consuming to prepare the control chart to which the control data needs to be transcribed, and that effective use is not made of the control data obtained.
Meanwhile, an apparatus is known in which data stored in the printer-processor are transmitted from the printer-processor to a central computer by using a data communication means, and the data are stored, processed, and displayed for a determination. However, since the printer-processor is not provided with a storage unit for storing data in a time series, only the data stored when an instruction for data communication was given are transmitted. Accordingly, there are numerous problems in that it is unclear whether or not the data obtained is novel, the amount of data is limited in light of the communicating time, and equipment is involved for returning the data collected in the central computer back to the printer-processor, in addition to the cost involved therein. Furthermore, to make an overall judgement of detected values and measured values, an accurate judgement of the data is difficult unless the periods of the data obtained are clearly known.
In addition, a method for measuring an image copied on a copying photosensitive material such as a test print varies depending on the copying apparatus. For instance, in a case where a density measurement is made of an image copied by a copying apparatus which is not provided with a density measuring section, the operator sets the copying photosensitive material with the image copied thereon in a densitometer which is separate from the copying apparatus, and then operates the densitometer to measure the density of the image. With this measuring method, since the operator's manual operations are required such as the setting of the copying photosensitive material in the densitometer and the operation of the densitometer, it is impossible to effect measurement of the densitometer at high speed.
Meanwhile, in a case where a density measurement is made of an image copied by a copying apparatus which is provided with a density measuring section for measuring an image density and in which control of a transporting system for transporting a copying photosensitive material and of a density measuring section is conducted separately, the operator sets the copying photosensitive material in the density measuring section so as to measure the density. With this measuring method as well, the operator's manual operations are required in the same way as described above, it is impossible to measure the image density at high speed.
Also, a copying apparatus is known which is provided with a density measuring section for measuring an image density and permits automatic measurement of the image density by synchronizing the operating timing of the density measuring section with a transporting system for transporting the copying photosensitive material. With this copying apparatus, the operator's manual operations are not required and measurement of the image density at high is possible.
However, with the copying apparatus which permits automatic measurement of an image density, it is necessary to position each image copied by the copying apparatus at a measuring position of the density measuring section. Conventionally, this positioning is effected by stopping the transport after the lapse of a fixed time upon copying processing. Consequently, since it is necessary to measure the elapsed time since copying processing with respect to each image, processing has been complicated. Also, positioning errors are liable to occur, so that it has been difficult to effect accurate positioning.
Generally, copying apparatus for copying images onto an elongated copying photosensitive material have a cutter section for cutting the copying photosensitive material, and a cutting portion of the image is positioned at a cutting position of the cutter section so as to cut the copying photosensitive material into image units. Consequently, with the aforementioned copying apparatus capable of automatically measuring an image density, the positioning of an image at the density-measuring position and the positioning of a cutting position of the image at the cutter section are conducted, so that the positioning processing has been complicated.
With the copying apparatus capable of automatically measuring an image density, since the measurement of an image density is conducted continuously with respect to a plurality of images copied onto the printing paper, it is necessary to control the image densities measured in correspondence with the images. Thus, in cases where post processing is effected with respect to each image, it becomes necessary to effect control by allowing each item of data on images to correspond with the respective images.
For this reason, there has been proposed a method of classification and control in which each item of data is made to correspond with each image by punching holes in printing paper, the number of such punched holes and the distance between adjacent ones of the punched holes being varied (refer to Japanese Patent Laid-Open Publication No. 63-234234).
However, with the aforementioned method of classification and control, in order to effect control by allowing the data on the images to correspond with the images, it is necessary to provide the copying apparatus with both a puncher for punching holes and a sensor for detecting the punched holes, so that the arrangement of the copying apparatus has been complicated.
In cases where the density of each image is automatically measured as post processing of each image, it is necessary to conduct measurement with the density-measuring portion of each image positioned at the density-measuring position. However, with the method of measuring the image density by detecting the position of the image by means of the punched hole, the sensor for detecting the punched hole needs to be provided in the vicinity of the density-measuring position, thereby making the arrangement of the copying apparatus complicated.
Furthermore, with the copying apparatus having the density measuring section for automatically measuring the density of an image, the level of an output signal from the density measuring section fluctuates due to fluctuations of a supply voltage or the like, so that the level adjustment o the output signal is conducted. However, there are cases where the supply voltage fluctuates after the level adjustment, in which case accurate density values are impossible to obtain.